Tool for reaming bushed bearings of engine connecting rods



July 23, 1929. F. G. WACKER I 1,721,392

TOOL FOR REAMING BUSHED BEARINGS OF ENGINE CONNECTING RODS Filed May 14, 1926 2 Sheetsheet 1 iii.

Lif g'a July 23, 1929.

F. G. WACKER TOOL FOR REAMING BUSHED BEARINGS OF ENGINE CONNECTING RODS Filed May 14, 1926 2 Sheets-Sheet 2 7? aerzzar' Patented July as, ieae. j I 1,721,892

rites Fries,

FREDERICK G. WACKER, or CHICAGO, rLLinoIs.

TOOL FOR BEAMING BUSI-IEZD :enanrnes or ENGINE conivnorrne'nons.

Application filed May 14, 1926. Serial No. 109,022.,

My invention relates to a tool for reaming of Figure. 7 Figure 9 is a plan view of a to exact desired diameter, and to true cylinfragment of the tool shown in Figure 8, showdricity, the Babbitt-metal bushings of split- I ing the clampingflmeans for the blade, and bearing connecting rods "such as are com- Figure lOis a perspective detail of a clamp- 55 monly employed in automobile construction; ing block employed-therein.

Accuracy of full area fit between the bushed The tool comprises a solid steel body of connecting-rod bearing and its coacting true cylindrical form (save where interruptcrank-pin is of recognized importance, and ed) and having a tang extension 11, the flatin the repair-servicing of automobiles the tened cheeks of which are for engagement 10 re-Conditioning of an engine-crank, by dressin a vise A, for the tool is to be held rigidly ing its crank pins to remove the results of While the connecting rod C to be reamed is Wear or distortion, makes it necessaryto remanually rotated about it to dress the bush bush the corresponding connecting rod bearing B, under a procedure of which more'will 'ings and dress them to fit the slightly-underbesaid. 1 15 sized crank-pins, Tools-have been provided Longitudinally the body 10 is deeply refor the reaming of such bearings, Widely adcessed, as at 12, to receive the cutting blade justable to accommodate a considerable range 13, which is preferably nearly of full-body of recognized crank-pin diameters, but with length, and of rectangular form in cross complexities of construction and operation, section except at its outer edge-surface which 2p and with substantial chance of error in atis slightly beveled fromv the forwardly-facing tempting to adjust for desired diameter; and Straight cutting edge Hand then more abone of the general objects of my invention ruptlybeveled as at 15 toward its rear face; is to provide a tool so simple and ineXpenthe fiat rear surface of the blade bearing sive in construction, requiring so little adsmoothly-against therear face of'the recess 25 justment, insuring such accurate excellence 12 and the front surface of the blade prefof per fo-rmance even in inexpert han'ds,'and erably lying p'arallel toand slightly in front so facilitatingthe work,-that a set of such of a diametrical plane of the cylindrical tools, respectively of diameters appropriate body. to the several recognized commercial sizes'of Itis purposed, for most effective operation, 0

crank-pins may most economically afford that the cutting edge 14 shall protrude only best service-station equipment for this Work, a minimal cutting distance beyond the cylincreasing the efficacy and facility of perinder surface of the body, its protrusion ,formance. y I being of the order of about athousandth of Other and further objects of my invention, Tan inch, (say, from a half a thousandth to of constructional and operative advantage, two thousandths) and to facilitate accurate will more fully appear from the following positioning of the blade for uniform protrudescription taken in conjunction with the ac-' 'sion', as well as to permit slight adjustment companying drawings, Wherein a primarily to take care ofv slight change of Figure 1 is an elevation of atool embodying depth of the blade as its cutting edge is 're- 40 my invention, in course of use. 7 Figure 2 is sharpened from time to time) adjusting an enlarged elevation from the cutting side. screws 16 are provided, extendin'gthrough Figure 3 is a cross-section on line 3 3 of the body 10 near opposite ends of the blade Figures 2 and 4; Figure etis a longitudinal and with their kerfed outerends below the section on the broken line 4% of Figure 2. cylindrical surface of the body. Of course 45 Figure 5 is an end elevation of a modified the blade shouldbottom firmly on these'potool embodying features of my inventioma'ndj sitioning screwsf a j H v Figure 6 is a side elevation thereof taken In'front of the blade the body is cut away: fromfthe leftof Figure 5. .Figure 7 is an. to provide chip-receptive space or clearance, end elevation of another modified tool emand means are provided for lockin the blade bodying features of inventien; Figure firmlyin position,and preferablym arrange- S is a sideelevatian thereof at the left that tends to draw tie blade firmly 'its forward edge 18, which is beveled to converge inwardly and to interfit with a correspondingly beveled front wall 19 of its receptive recess. Machine screws 20 countersunk into the outer face ofthe locking bar and passing therethrough with a looseness of fit,are threaded into the holes 21 of the body,so that thescrew axes are pref- .erably parallelwith the-plane of the front faceofthe blade. Thus, as the screws 20 are tightened, thel ocking is both drawn inwardly and'wedged rearwardly, tending to draw the bladelli down firmlyinto' engagenientwith its bottoming screws 16 as well as to force the blade into tightest contact with I the rear face recess ,12, Of course, when drawn home the locking bar l1es whollyw1thin the cylindrical confines ofthe body sothat there is left opena space 22, beyond the'locking bar and in front of the blade, adequate for chip-receptive purposes.

7 Erom Figure 1 and the (greatly exaggerated) illustration; of Figure 2,, the intended dressing, operationmay be under- .stood. v The splitv bushing is positioned in the two halves of the split,bearing-annulus C;,-; thetw halves of which maybe drawn together by theusual. bolt and nut arrangemelntc as desired, the customary shims 8 being remoyed or reducejd as desired. The mechanic places the hushed connecting rod around the reamer with its cutting edge enthe edge of one of the bushing-halves,

and tightens thenuts 0 as suggested by the illustration of wrench-w in Figure 1. Then he turns the connecting rod manually halfway. around the reamer, producing .a cutof one bushing-half as exaggeratedly'shown 1n F gure Then he tightens the nuts 0 to the fresh-cut bushing surface into engagement with the cylinder surface back of the cuttingblade (contact being substantially complete because of the fineness-of the cut),

. andthen makes his first cut on the other half o fithe bushing. Continuation of this proeedure dresses the bushing with great aecuraey and uniformity to the predetermined size for which the tool is appropriate and which, in commercial reconditioning practice, will'usually represent a di ameten slightly less than some standard crank-pin'diameter tofit the reconditioned cranki-pin a'lthough sizes appropriate 'to standard, new work may beprovided of' course.

In the construction shown in liigures and 6, the blade-recess 12 is of width quite snugly to receive the thickness of blade 13,

the chip-space 22 in front of the blade is formed by cutting a fiat surface in the body at right angles to the front edge of the recess 12, and the clamping of the blade against the rear wall of the recess is efl'ected'by a suitable series of screws 25 extending through a portion of the body substantially at right angles to the front face of the blade and with their heads countersunk in suitable recesses 26 in the body. I g 1 I In Figures 8 to 10 the blade-recess 12 is likewise made narrow, quite snugly to receive the blade 13, and the 'cliip-space'is afforded formin gga flat 22, as above described, and the blade-locl'rin gy arrangement includes screws .28 entering the body insubstantial parallelism with the frontface of the blade near opposite ends ofthe latter, eacli' such screw being countersunk in a clamping plug 29 of taper ng or frustro-conical shape save that its blade-engaging surface is a flat face 30 parallel to theaxis of the screw. Such plug 29 seats within a corresponding conical recess '31 that intercepts the blade-recess Y12 and. permits the plug-face 30 to engage the blade. When the plug is drawn down by the screw 28, its slight looseness of iit ab'out the screw and also within the recess 31 caiises it to draw the blade inwardlyfupon the botto'ming screw'slfi as well as to force the blade against the rear wall of its recess 12*.

While I have herein described in some detail modified embodiments of invention for purposes of full disclosure and to indicate that in some of its det'ails'changes mayreadily be made, itwill be understood that other changes in details of construction may be made without departure from theispirit of my invention within the scope of the ap-' pended 7 claim.

I'claim: I I

A tool for the purpose described, which comprises a generallycylindrical, rigid body which serves as the sole supportfor' the tool in the bore to bereamed, said body having a recess extending longitudinallysubstantially throughout the length fof the body with'its bottom surface paralleling the axis of the body, and one ofthe sidewalls of said recess being straight and its other, sidewall tapered inwardly, a rectangularly shaped cutting blade having its bottom edge paralleling the bottom of said and its one side edge paralleling and'abutting the straight wall of said recess, which straight wall is so located as to position saidbla de'radially in said body, a plurality of adjustable abutment screws carried by'said body dppositesaid blade, the

inner ends of saidscrews extending through sa d recess bottom to support said blade, and a clamp ng devlce which serves as the sole means of "holding said blade in said recess on said screws which comprises a block mounted in said recess at one side of said blade, said block having a straight side en-' gaging a straight side of said blade and having a tapered side engaging the tapered wall of said recess,' and screws freely passing through said block and entering threaded openings in said body parallel to said blade for drawing said block downwardly to ad- I justably force said blade laterally and downwardly into its clamped cutting position.

In testimony whereof, I have subscribed my name.

FREDERICK G. WAGKER. 

